Method for applying metal forming lubricants



March 26, 1935. R. c. WILLIAMS METHOD FOR APPLYING METAL FORMING LUBRICANTS Filed March 16, 1932 INVENTOR Robert C. l V/l/l'ams BY M ATTO NEY Patented Mar. 2 1935 UNITED STATES PATENT OFFICE METHOD FOR APPLYING METAL FORMIN LUBRICANTS Robert C. Williams, Columbus, Ohio, assignor to The Ironsides Company, Columbus, Ohio, a

for applying metal forming lubricants. It has to do, more particularly, with a novel method and apparatus for applying lubricants to metals before they are subjected to various metal forming operations. It is particularly applicable for use in applying lubricants to wire'before and during the wire drawing operation, although it is not limited thereto.

It has been a common practice in wire drawing to use various fluid lubricants to facilitate the passage of the wire through the dies. Soap solutions and dispersions of tallow or other fats in soap water are commonly used for this purpose. The most common method used in applying these lubricants to the wire has been to splash such lubricant on the wire and dies or to submerge the wire and dies in a bath of such lubricant. However, these methods of applying the lubricants to the wire have not been very satisfactory.

Another prior art method. which is used for the purpose indicated, consists in passing the wire through a bath of lubricant and heating that portion of the wire which is in the bath to incandescence,- by means of passing an electrical current therethrough. The bath through which the wire is passed is a hydro-carbon bath and when the wire is heated to incandescence it decomposes some hydro-carbon and deposits carbon on the surface of the incandescent section of the wire, in the form of graphite. This graphite is adapted to act as a lubricant. When certain types of wire, such as copper wire, are heated to incandescence, the wireis injured.- For this and other reasons, this method has not proved satisfactory.

One of the objects'of my invention is to provide a novel method and apparatus for applying a lubricant to a metal, before it'is subjected to the forming operation, which will not be injurious to the metal in any way.

Another object of my invention is to provide a method and apparatus for applying a metal forming lubricant which will be more emcient than. any method and apparatus used heretofore and by which the lubricant may be applied in such a manner as to decrease the wear on the die or other mechanism used in the forming operation.

Another object of my invention is to provide a method and apparatus for the purpose indicated by which the lubricant may be applied in such a manner that the amount of power heretofore required in such operation will be substantially reduced, and the breakages, which have heretotore been prevalent in metal forming operations, will be reduced to a minimum.

1932, Serial No. 599,213

A further object of my invention is to provide a novel method and apparatus for the purpose indicated by which the lubricant may be deposited on the metal in a uniform coating and consequently, the article formed will be of a better finish and will have more uniform properties.

In its preferred form my invention contemplates the provision of a method of applying metal f orming lubricants by means of an electrical current. The lubricants most commonly used in metal forming operations consist of some substances which are dispersed in water or other dispersion mediums in the colloidal state, or as coarser dispersions. In my method I set up an electric field such as that set up in a direct current electrolytic cell, in the bath of lubricant. These dispersed particles possess electric charges. When the electric field is set up in a bath of such lubricants, these dispersed particles migrate to the electrode, having an opposite charge, and form a film on such electrode. If the dispersed particles are negatively charged, I make the wire, to be drawn, the positive electrode. If the particles are positively charged, I make the wire the negative electrode so that the lubricant particles will be deposited thereon. This principle which I use is known generally as cataphoresis or electrophoresis.

The apparatus which I preferably use in performing this method comprises a tank which is adapted to contain the lubricant bath, which may be some form of dispersion. The dies through which the wire is adapted to pass, in order to be drawn, are mounted in this bath. The wire is adapted to be drawn through the bath and is provided with an electrical charge which is opposite to that of the dispersed particles of lubricant. This wire is charged by connecting the dies to some source of current, or in some other suitable manner, and the wire is adapted to form one of the electrodes which is used in setting up the electric field. A second electrode is mounted in the bath in proximity to the wire, and this electrode is provided with a charge like that of the dispersed particles. In this manner the electrically charged dispersed particles will migrate from the one electrode towards the wire and will be deposited thereon.

The preferred form of apparatus which I may use in the performance of my method is shown in the accompanying drawing wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a diagrammatic illustration, partly in section, showing a form of apparatus which I may use in the performance of my method.

Figure 2 is a transverse section of the tank showing the novel form of electrode which I may use and showing one of the capstans which is some substance which is to be used as the lubri.

cant. This bath may comprise any type of fluid dispersion which exhibits the phenomenon of electrophoresis which is useful in lubrication. Openings 2 and 3 are provided in ends of the tank 1 and the wire 4, to be drawn, is adapted to pass through these openings.

Dies 5 and 6 are mounted on the bottom of the tank in the lubricant bath in any suitable manner. -These dies may be of any suitable type. The wire 4 is adapted to be drawn through these dies in order that it may be formed. After the wire passes through the die 5 it is wound around a capstan '7 which is rotatably mounted in the bath. The capstan 7 is rotatably mounted on a suitable support 8 which is secured to the side of the tank 1. After the wire passes through the die 6, it is wound around the capstan 9 which is mounted in the bath in a manner similar to the capstan '7. The capstans 7 and 9 may be positively driven through the medium of gears 7' which are mounted on the ends of the shafts on which the capstans are mounted and which are openly connected to some power unit. By driving these capstans the wire may be drawn through the-dies.

The wire 4 is adapted to be charged in some suitable manner. This is preferably done by connecting the dies 5 and 6, which are in contact with the wire, to a source of current. A wire 10 is connected to the die 5 in and the opposite end of this wire is connected to a suitable source of electricity 11. This wire 10 is provided with a branch wire 10' which issuitably connected to the other die 6'. It will be readily understood that currentwlll be conducted from the source of electricity 11 through the wires 10 and 10', through. dies 5 and 6 and into the wire 4. However, if desired'the charge may be applied to the wire 4 through the capstans or through some means outside of the tank, or in any other desired manner.

An electrode 12 is mounted adjacent the die 5 in any suitable manner and an electrode 13 is mounted adjacentthe die 6.. These electrodes are preferably of the shape shown in the drawing and may be made of any suitable material. They comprise a cylindrical body portion 14, which is comparatively long. However, the shape of these electrodes may be varied. This body portion 14 is provided with aslot 15 formed in the lower side thereof. This slot 15 extends for the entire length of the electrode so that the wire may slip therethrough. These electrodes 12 and 13 are mounted in surrounding relation to the wire 4 in the bath. They may be mounted on supporting members 13' which are fastened to the side of the tank.

The electrode 12 is connected to a wire 16 which is also connected to the source of electricity 11. A branch wire 16' is connected to the wire 16 and the opposite end of this wire 16 is connected to the electrode 13. It will be understood that the wires 10 and 10', dies 5 and 6, wire 4, the fluid any suitable manner lubricant, electrodes 12 and 13, and wires 16 and 16' form a complete circuit. A variable resistance such as a rheostat 17 and a switch 17' are mounted in the circuit. By means of this rheostat and switch, the amount of current flowing through the circuit may be varied. An ammeter 18 is also provided in the circuit so that the amount of current in the circuit will be indicated. Although I have shown the dies 5 and 6 connected to the positive terminal of the source of electricity and the electrodes 12 and 13 connected to the negative terminal, when desired this may be reversed. It will also be understood that the mounting for the dies, capstans and electrodes may be insulated from the walls of the tank by any suitable insulating material which is indicated by the numeral 20in the drawing. It willfurther be obvious that any number of dies, capstans and electrodes may be provided.

When using the apparatus just described, in the performance of my method, I first place the lubricant in the tank 1. This bath .of lubricant may consist of any suitable lubricating substance dispersed in any suitable medium. The wire 4 is drawn through the bath and it is charged. If the dispersed particles of the lubricant substance are negatively charged, as they are in most cases, the wire is given a positive charge. The wire 4 passes through the electrodes 12 and 13 and these electrodes are provided with a charge which is the same as'that possessed by the dispersed particles of lubricant.

As shown in the drawing, the electrodes surround the wire 4 and will concentrate the efiect of the chargepossessed thereby, on the wire. The wire 4 will be drawn through the electrodes 12 and 13 at such a speed that the fluid, which is contained within such electrodes, will be constantly renewed. Furthermore, the capstans rotating in the bath will agitate the fluid of the bath and will also tend. to renew the fluid within the electrodes. In this manner a fresh supply of fluid will be provided within the electrodes at all times. This will insure that there will always be a sufficient quantity of dispersed lubricant particles in the dispersion within the electrodes.

As previously stated, the electrodes are provided with a charge of the same kind as that possessed by the dispersed particles and the wire to be coated with lubricant is provided with a charge which is opposite to that possessed by the lubricant particles. Under such conditions the dispersed particles will migrate from the electrodes towards the wire and'will be deposited thereon. I have found by numerous laboratory experiments that wire, which is coated by the method and apparatus setout above, can be more easily drawn through the dies and that markedly superior lubricating effects are thereby obtained. It will be understood that although I have only illustrated a method and apparatus for applying a lubricant in the wire drawing operation, that my method and apparatus is not limited to wire drawing but may be extended to other metal forming operations.

.As previously stated, soap solutions and dis persions of tallow or other fats in soap water are commonly used for this purpose. My process is particularly adaptable to depositing lubricants of this type which owe their lubricating value .to organic radicals or component parts.

By using the method and apparatus set out above, I have been able to produce an eilective coating of lubricating materials on the wire prior to its passage through the dies. As an example of the effectiveness of this process, I may cite the case where a solution of an ordinary commercial, high solidifying point, sodium soap was used as the lubricant on a copper wire. This copper wire was of .0253 inch diameter and was drawn through a .0225 inch diameter tungsten carbide die- The wire was charged positively and the dispersed soap particles were negatively charged. A carbon electrode, which was also negatively charged,

. was introduced into the bath in proximity to the wire to complete the circuit. Under the influence of 22.5 volts D. C. and a current of .022 amperes, the soap particles migrated towards the wire and were deposited thereon. The pull required to draw the wire through the die, after the wire had been coated with the lubricant in such a manner, was only 8 pounds as compared to 13 pounds when electrical coating of the wire with the lubricant was not employed. My novel coating process, therefore, efiected a reduction of approximately 38 percent in the force required to draw the wire.

7 The current density in the above example was .0096 of an ampere per square centimeter. It will be readily understood that the voltage, current, and current density may be varied to suit the particular case. The current density dedepends upon the area of the wire surface exposed in the zone of influence of the electrical circuit. It also depends upon the degree to which the wire becomes coated, the speed with which the wire passes through the zone of influence of the electrical circuit, the voltage, the conductivity of the lubricant fluid, the proximity and design of the one or more neighboring electrodes, and other possible factors. These and other factors may be adjusted to suit particular cases without departing from the fundamental basis or scope of my invention.

Similar benefits have been derived through the application of this process and apparatus in the drawing of stainless steel wire of the 18 percent chromium and 8 percent nickel type, nickelchromium alloy wire, and iron wire. It will be understood that, in practice, the application of this new and useful process and apparatus in applying lubricants to metal before the metal forming operation, is not limited to use in drawing wire of any particular composition. It will also be understood that 'my method and apparatus may be used with any particular type of fluid dispersion, which exhibits the principle of cataphoresis or electrophoresis.

It will be readily understood from theabove description that I have provided a method and apparatus for the purpose indicated, having many advantageous features. My method is extremely simple and easy to perform. The lubricants are applied by my method and apparatus in such a manner that the amount of power required to form the metal is reduced to a minimum and wear on the various metal forming tools will be substantially decreased. Then too, the breakages which have heretofore been prevalent in metal forming operations will also be considerably reduced. Likewise, the metal coated in the manner set out will not be iniured in any way. Furthermore, the lubricant will be deposited on the metal in a uniform coating so that after the metal has been formed it will have a better finish and more uniform properties.

Havingthus described my invention, what I claim is:

1. The method of applying metal-forming lubricantswhich comprises placing the metal in a bath comprising a fluid system having charged lubricant particles which owe their lubricating value to organic radicals or component parts and which have inherent lubricating qualities both before and after being applied to the metal, and causing the charged particles to migrate towards and to be deposited upon such metal by setting up an electric fleld in such bath.

2; The method of applying metal-forming lubricants which comprises placing the metal in a bath comprising a fluid system having dispersed charged lubricant particles which owe their lubricating value to organic radicals or component parts and which have inherent lubricating qualities both before and after being applied to the metal, and using the principle of electrophoresis to cause said dispersed charged particles to migrate towards and to be deposited upon such metal.

3. The method of applying metal-forming lubricants which comprises placing the metal in a bath comprising a fluid system having dispersed charged lubricant particles which owe their lubricating value to organic radicals or component parts and which have inherent lubricating qualities both before and after being applied to the metal, and causing the charged particles of lubricant to migrate towards and to be deposited upon said metal by supplying an electrode, which is disposed in said bath near said metal, with a charge like that of the charged lubricant particles and simultaneously supplying said metal, which is to receive thelubricant, with a charge opposite to that possessed by the charged lubricant particles.

4. The method of applying metal-forming lubricants which comprises continuously moving the metal through a bath comprising a fluid systein having dispersed charged lubricant particles which owe their lubricating value'to organic radicals or component parts and which have inherent lubricating qualities both before and after being applied to the metal, and causing the lubricant particles to migrate towards'and to be deposited upon said metal as it moves through the bath by providing an electrode, disposed in said bath in proximity to the path of movement of said metal,

witha charge like that possessed by the lubricant particles, and supplying the metal with a charge opposite to that of said charged particles.

5. The method of applying metal-forming lubricants to wire, preparatory todrawing, which comprises passing a wire continuously through an electrode which is disposed in surrounding relation thereto and is mounted in a bath comprising a fluid system having dispersed charged lubricant particles which owe their lubricating value to organic radicals or component parts and which have inherent lubricating qualities both before and after being applied to the wire, and causing the charged particles of lubricant to migrate towards and to be deposited upon said wire by supplying said electrod with a charge like that of the lubricant particles and supplying said wire with a charge opposite to that possessed by the lubricant particles and agitating the fluid as the wire passes therethrough so that the fluid in said electrode will be continuously replaced.

ROBERT C. WILLIAMS. 

